Traffic signal



June 28, 1938. R. M. ALLEN 2,121,772

TRAFFIOSIGNAL Filed Dec. 27, 1927 3 Sheets-Sheet l June 28, 1938; R, L 2,121,772

TRAFFIC SIGNAL Filed Dec. 27, 1927 s Sheets-Sheet 2 R. M. ALLEN TRAFFIC SIGNAL June 28,

, Filed Dec. 27, '1927 s sheets-shea s attozneg Patented June 28, 1938 UNITED STATES PATENT OFFiCE TRAFFIO SIGNAL Roy M. Allen, Bloomfield, N. J. Application December 27, 1927, Serial No. 242,755

4 Claims.

way passes through the length of the town and.

local traffic only uses the cross-ways. In such case if ordinary automatic signals are employed, the through traffic is stopped at regular intervals and thereby delayed needlessly, when there are no vehicles at all on the cross-ways. A similar condition may and does exist in cities, where boulevard trafiic for example is denser than cross-way traffic. made to remedy this by shortening the time of passage for the cross-ways, and giving the through traffic on the boulevard the right of way.

I attain my object by providing signals of a type which I may call semi-automatic, that is to say, which may be operated by hand or by an approaching vehicle on a cross-way, but in case there are several vehicles or the time of use of the cross-way exceeds a certain predetermined limit, the signals will then be changed to restore the through traflic its right of way. By this means there is no interruption of the through trafiic at all unless there are actually vehicles desiring to cross on the cross-ways. Special provision of course will have to made in such a. system for left hand turns and the like.

As examples of the means by which I attain my object, the usual green, orange and red lights may be employed showing two ways up and down the boulevard and on the cross-ways. With ordinary operation the green lights will remain set for the boulevard continuously as long as there is no traflic on the cross-ways but when a vehicle approaches on a cross-way, the driver may actuate the signals at that crossing, changing to orange for the boulevard and thereafter automatically changing at the expiration of the Warning period to red for the boulevard and green for the cross-ways. After the lapse of a predetermined time, say forty seconds, to allow the cross-way vehicles to cross, the lights will automatically go to orange again, and after five or ten seconds more to red for the cross-ways and to green for the boulevard, thus to remain until another manual or equivalent operation makes a change.

To actuate the signals, circuit closers placed on Various attempts have been.

the right hand side of each cross-way at the intersection with the boulevard, are suflicient. These may be either push buttons on special posts at the curb, within reach of a driver, or devices similar tothe platform of a vehicle scale. The former will probably be employed where a cheap or temporary installation is desired for test purposes, or where the cross-way is too nar-v row for a platform in one-half thereof, and the latter where the installation is permanent. In

either case the actuation of the circuit closer by hand or by the weight of the vehicle trafiic on it, will close the circuit of a relay or relays which in turn control the light circuits. The first impulse which closes the cautionary light circuits, and

interrupts the green light for the boulevard, also sets a timing device which will run for the prede termined time, as forty seconds, required by. a vehicle in crossing .andwill then act to restore all signals, automatically changing both ways to 55,0

orange and thereafter going green to the boulevard and red to the cross-ways.

Where numbers of vehicles are following each other upon a cross-way, either in ordinary traffic or in such cases as that of a funeral, either a spe- 25 cial timing device must be employed or repeated operation of the circuit closer be made. My device will operate either in this manner to keep the crossing open across the traiiic for one time unit or a number of units at a time, or else to open and close it after the first closure at periodic intervals only. The determination of which of these two methods of operation shall be followed is a question of policy and not of mechanics.

I My invention is illustrated in the accompanying drawings, in which Fig. 1 is a plan view of a timing mechanism adapted to automatically control signals which are initially set up by a manual or platform coritrivance.

Fig. 2 is a front view of the dial or indicator of (w the same.

Fig. 3 is a sectional view on the line 3-3 of Fig. 1, looking in the direction of the arrows.

Fig. 4 is a diagram showing the signals at one 5 crossing, with the control relays and timing mechanism therefor.

The general arrangement in Fig. 4 will first be referred to, before describing the apparatus. In

this diagram, I is an operating device having a a circuit closer 2 controlling circuit through wires 3-4, and supposed to be located at an intersectionof a lateral way with a main way or boulevard. The contact 2 may be operated either by movable platform 1 preferably portable, over g5 which vehicles may be driven, or by equivalent means such as a push button or manual switch on a pole. The wires 3-4 are the starting wires for initiating a change in signals to permit trafiic to pass on the cross-way. Current is supplied to this circuit from a low voltage source connected across the terminals 5-6, and includes primarily winding of a relay I which may be called the master relay. 8 is the timing device, which when started by the energization of the relay I runs for a predetermined length of time at a uniform speed so as to regulate and control the right of crossing initiated at the platform I. This timing device has a contact such as 9 which is normally closed against the companion contact I9 forming a terminal of the circuit 3 of the master relay I. The moving contact 9 is connected through the body of the timing device 8 (or in any other manner) to return wire I I connected to the energization circuit. The timing element 8 is mounted on a shaft I2 which is rotated as stated at a uniform speed by means of a device such as a spring in which energy is stored when the contact device 2 or equivalent is operated, and its rotation is regulated by the escapement mechanism 41. Timing contacts I3, I4, I5 and I6 are carried on movable arms shown at II, I8, I9 and 29 in Fig. 2, to be presently referred to. These arms are adjustable around the shaft in order to predetermine the times at which the contact 9 on the element 8 will encounter and make contact with the respective timing contacts. The contacts I3 and I5 are connected through wire 2I to relay 22 which has two windings, an energizing winding 23 and a locking winding 24. The energizing winding is connected by return wire 25 to the energizing circuit 5-5. The contact I4 is connected through wire 26 to the energizing winding 28 on relay 21 which also has a locking winding 29. The energizing winding is connected on the return side to the wire 4 and so to the terminal 5 of the energizing circuit.

The relay 22 through its locking armature 22a controls the relay 39, and the relay 21 through its locking armature 210, controls the relay 3|; and these two relays 39-3I are signal relays which control the signal lamps 32, 32a, 33, 33a, 34, 34a, etc. Relay 22 has a second armature (or equivalent contacts 2212) which controls a short circuit 35, 36, 31 around the locking winding 29 of the relay 2I; and conversely relay 2! has a second armature or its equivalent 21b whichv controls a shunt 3839 around the locking winding 24 and its contacts of relay 22. The purpose of 'these shunts will be apparent from the statement of operation.

When the master relay I is'excited, the timing device 8 is rotated by means of energystored in a spring or equivalent device. This is indicated in the diagram, where the shaft 49 is shown as carrying a ratchet wheel 48 adapted to be turned one tooth at a time by the pawl 4! on the armature lever 42 of the electromagnet 43, whose circuit 44 is closed by the contacts 45 of the master relay when the latter is energized. The armature lever 42 is shown with a normally closed back contact 46 which opens when the armature is attracted.

S S S S are ordinary snap switches to open the low voltage circuits and control the lamps 32, 32a, 33, 33a, 34, 34a under special conditions, as may be desired. In ordinary operation the switches S and S are closed, and the others are open. No current is flowing in any part of the circuit as it stands for open traffic or without trickle charger.

on the main way or boulevard except the current necessary to light the green light 32 for said way.

'It will now be understood that my operating circuits and apparatus consist of three parts: first, the street operating device of whatever form; second, the street signal means, which may be means already installed, preferably with three signals, red, green and orange (as commonly used, omitting the orange if not wanted, which can be done without any other change in the apparatus or circuit) and third, the timing means and the relays and switches, together with a source of direct current. The third division of the apparatus is enclosed in a weather-proof box, which contains the timing means, the relays and switches, and if direct current is not available from the 1l0-volt circuit, a storage battery, with The lamps are shown in condition for normal operation with the green light 32 showing on the main way or boulevard, and the red lamp 32a showing on the crossway. ThellO-volt current lighting these lamps is fed through the back contacts of relays 39-3 I, which are standard power type relays, of a size to carry and open the current required for these lamps. The relays I, 22, 27 are all of standard telephone type, operating on a small current and only carrying sufiicient energy to operate the other relays.

The timing device of Figs. 1, 2, 3 will now be described. Parallel frame plates 49-59 are connected together by posts or the like and are fitted with bearings for the power shaft 49, and theescapement shafts 5!, 52, 53. The power shaft carries a gear 54 meshing with a pinion 55 on shaft 5I whosegear wheel 55 meshes with pin.-

.ion 57 on shaft 52 which in turn carries scape wheel 58 cooperating with the anchor escapement 59 which has a verge rod 59 and a Weight BI adjustable thereon to time the gear train 58, 59, 54, and thereby time the power shaft 49 inits rotation. This power shaft always turns in the same direction, being prevented from reverse motion by the stop pawl 62 conveniently pivoted on the upper part of the magnet frame 63. The magnet structure 43 comprises a pair of solenoids 54-55 with the upper half of their cores fixed on the yoke 69 and serving thereby to support the solenoids 6495 on the frame 61 which at its lower end carries armature 42 constituting the operating lever of the machine and having pivoted to it the operating pawl 4! which works the ratchet 48. Between the upper element of the frame and the armature 42 is a compression spring 68 adjustable as to its tension by means of screw 69 and lock nut I9. Yoke II carries the lower or movable halves of the two cores I2, which normally rest in the position shown in Fig. 3, retracted. The yoke II is straddled by the armature lever 42 and prevented from falling away by the strap retainer I3, upon which for convenience is mounted the contact spring 46 before referred to and shown in Fig. 4. The spring cooperates withan adjustable contact 14 carried on an insulated support in the usual manner. A mechanical backstop for the armature 42 and its pawl 4| is provided at I6, adjustably secured to the frame.

Referring particularly to Figs, 1 and 2, the contacts I3, I4, I5, I6 are shown mounted on the adjustable arms I1, I8, I9, 29 which are locked when set by the thumb nut I1. It will be understood that the angular position of these arms, and the relative distance between the contacts I3, I4,

etc. determines the time intervals between the lighting and extinguishing of the several lamps, 32 3211., etc. The contact 9 which in Fig. 4 is shown as a projection on the disc 8, is shown in Fig. 2 as acontact arm upon the shaft 5|, which is therefore the timing shaft. In order to facilitate the setting of the several arms and the angular measurement of their distances apart, I provide graduated circle l8 supported in any suitable way as upon posts 19, and in order to permit the adjustment of the contacts without breaking circuit, flexible leads are soldered to the tips of the contact springs at m.

.-..In operation, when the circuit of the solenoids is closed the armature lever 42 is pulled up and the pawl 4! is lifted the distance of one tooth, the circuit of the magnet being at the same time broken at the back contact 46, and the spring 68 being placed under tension heavy enough to store up sufficient energy to turn the timing device 8 with its contact 9 through one complete rotation, at a rate determined by the adjustment of the escapement or timing mechanism 4'1. Great latitude in adjustment is permitted by the moving of the weight or ball 5! up and down on the verge rod 69, so that the cycle of rotation can be set for anything from one-half minute to at least three minutes.

The entire showing of my timing device in the present application is necessarily somewhat diagrammatic, as this piece of apparatus must be designed to meet the service conditions in any particular case, e. g., if a long cycle of operation is necessary the escapement must be modified and probably a stronger spring for operating it would necessitate the placing of the magnet structure 43 to the left of the escapement in Figs. 1, 3 and 4, with a longer armature lever 42, so that the distance through which the magnets exert their pull would be greater.

It will of course be understood that for the sake of clearness of illustration Fig. 3 shows the frame and working parts in section, with the parts shown in Fig. 2 removed therefrom. Also, in the drawings, details are eliminated so far as possible,.and it will therefore be understood that I reserve the right to add any known or suitable features that may be necessary or desirablein commercial operation, without departing from the invention.

In Fig. 4, I have shown in dotted lines circuit connections for substituting distant control for the local control of the crossing signals. Thus, taps are taken off at 80, 8| to contacts 82 of relay 83 controlled through wire 84 from a distance, to disable the master relay 1 which is locally controlled. When the distant control relay 83 is thus got into service it is necessary to break the wire 3 at which may be done by any suitable and convenient form of switch.

Similarly, taps 86, 3'1, 88, 39, 99 are taken off from the parts l2, l3 and l5, I6, 25, and 14 respectively by which all the local circuits and all the local pieces of apparatus can be controlled by impulses through wires 91 to inclusive, while the relay 83 remains energized. These wires shown in dotted lines may be in a cable transversing the entire length of the territory to be served, or the boulevard or principal way, and there may be taps taken off at every crossing, so that all or a number of crossing signals may be operated simultaneously, and uniformly from a common point.

Disregarding the dotted lines in Fig. 4 the operation of my system as thus described, is as follows: when a car closes the contact 2 of the street device I, current flows from the 6-volt source through the following circuit:- 5, 4, 3, .1, 3, 82 (when relay 83 is deenergized and switch 85 open), 10, 9, l2, H, B. This energizes the relay 1 which pulls up its armature and closes the contacts 45, whereupon current from the same source flows through the following circuit: 5, 4, 44, 45, 44, 43, 44, 49, 42, 44, i2, H, t.v The electromagnet 43 becoming energized, pulls up its armature lever 42, places the spring 38 under tension, and lifts pawl 4| to the next tooth of the ratchet 48, at the same time breaking its own circuit at contacts 45 and E4. The spring tension immediately produces a downward pressure upon the engaged ratchet tooth, the whole gear train including shafts 4i 5!, 52 commences to turn, and continues to turn for such time and at such a rate as has been predetermined by the adjustment of the weight 6! on the rod 69. The turning of the shaft 5| turns the timing element 8, which is. the same as the contact arm 8 in Fig. 2 and the contact 9 is thereby removed from the fixed contact In and after predetermined intervals of time is brought into engagement successively with contacts l3, l4, l5, I6, it. On its leaving the contact 43, the circuit of relay 1 is broken, whereupon that relay lets go its armature and breaks the circuit of the electromagnet 4-3, which therefore cannot again pull up its armature until aftcr the timing element 8 shall have made one complete rotation. When the contact 9 engages contact l3, it closes the following circuit: 5, 25, 23, 2|, l3, 9, l2, 41,6. This energizes electromagnet which pulls up its armature 22a.-22b. The first of these closes the following circuit: 5, 96, 91, relay 39, 98, 22a, 24, 31, 6. Thus the relay 39, which in turn pulls up its armature, breaks the circuit of the green lamp 32 on the main way and the red lamp 32a on the cross-way and through its front contact supplies -volt current to both the orange lamps 33-33a showing on the main way and the cross-way respectively.

As the timing device proceeds in its rotation, contact 9 engages with contact 54 and closes the following circuit, 5, 99, 28, 26, i4, 9, l2, H, '6. This energizes relay 2B, which pulls up its armatures 21a and 2112- the first of which closes the following circuit: 5, "l9, 3!, 19!, 2'la, 29, I92, 6. The second armature closes the following circuit: 22a, 38, 2%, 39, 31. As this is a short circuit around the locking circuit 24 of relay 22, the latter relay immediately lets go its armature, which breaks the circuit of the ralay 32, which in turn lets go and extinguishes the orange lamps 33-4311. It is prevented from relighting the lamps 32-32a however by the simultaneous energization of the relay M, which opens the circuit I03 leading from the ll0-volt terminals to the contacts of relay 39, and at the same time closes the circuit Hi4 of the red lamp 34 on the main way and the green 34a on the cross-way.

Through its armature 21a the relay 2? has closed its own locking circuit through winding 29, and this condition therefore prevails until the timing device contact 9 reaches and engages the contact 15, whereupon it closes the following circuit: 5, 25, 23, 2!, l5, 9, l2, ll, 6. This again energizes relay 22 the armature 22bof which closes the following shunt circuit around the locking contacts of relay 2?: 21a, 35, 22b, 36, I92. The relay 2? therefore immediately lets go its armature, deenergizing relay 31, which ex.- tinguishes the red lamp 34 on the main way and the green lamp 34a on the cross-way. At the same time, the armature 22a of relay 22 being attracted again closes its own locking circuit and also the circuit of the relay 3B, which thereupon pulls up and lights the two orange lamps 33-3311 looking down the main way and the cross-way respectively.

The timing element 8 continues the rotation until contact 9 reaches contact l6, whereupon it closes the following shunt circuit: 22a, H35, l6, 9, l2, ll, 31, 24. Relay 22 being disabled by this shunt circuit lets go its armature, deenergizing relay 30, extinguishing the orange lamps and relighting the green lamp 32 on the main way and the red lamp 320. on the cross-way. The timing device then continues its rotation until the contact 9 reaches the fixed contact l0, whereupon it stops by reason of the limit of travel of the armature lever 62, whose contact 46 has in the meantime reengaged its anvil contact It. Thus all the parts are restored to their normal condition after one rotation of the timing device 8.

In the event that no other car is waiting on the cross-way at either side of the main way, the contact 9 stops at contact l0 and the green light 32 remains lighted indefinitely; but on the other hand if a car is standing on the platform I of the street'device awaiting a chance to cross, when contact 9-40 is established by the contact arm or timer 8, the timing device is immediately reoperated and the contact arm 8 will continue to rotate so long as trairic may demand.

This timing device provides, within limits, for making the time of a complete cycle anything that may be desired, and if divided up the total time of the cycle so that each step in the operation may have any fraction determined upon; so it is evident that extreme control can be secured to meet all traffic conditions. However, should it be necessary under some city trafiic conditions to vary the operation for a portion of the time during certain hours of the day, this can be accomplished by the use of distant control (with 6 wires for full metallic circuit), and the use of relay 83, which cuts off local operation, While impulses sent out over the several Wires 9| to inclusive from a central control station replace the contacts produced by the arm 8 engaging the fixed arms !3, l4, i5, 56. As already stated, in this way all the signals on a street several miles long may be operated simultaneously, if desired, as is now done in many cities.

It should be noted that while I have shown only two sets of lamp signals at the left hand side of Fig. 4, there may be as many or as few of these as are desired in any particular case. The green lamp 32 and the red lamp 32a may typify two pairs of signal lamps looking in opposite directions on the main way or boulevard and on the cross-way, respectively; or in the event that there are more than two ways intersecting at the particular point, there may be as many more of these lamps as are necessary to block the cross ways. The main feature is that the boulevard or main way is normally open to trafiic, and is held so unless trafiic actually approaches from a cross-way, which initiates a change in the signals, thereafter carried through its various phases and completed automatically by the timing device.

Hitherto I have discussed this invention as applied to motor trafiic on highways, only. It will be noted however that I have used the word ways instead of roads or streets. This was done in order to include other sorts of traffic than motor trafiic only, viz: railroad, and. even a water traffic where applicable. Railway traflic iswell within the scope and purview of the invention, and in so far as the present invention is applicable thereto in its entirety or any of its parts, such application is contemplated by me and is intended to be covered in the appended claims.

It is to be observed that whether used for rail traffic or road traffic, and whether the crossway trafiic consists of isolated single vehicles or of a stream of vehicles across the platform I, the proper adjustment of the arms I1, l8, I9, 20 can be made to always provide for a definite period from I 4 to IE for freedom on the cross-way, and an equally definite period from IE to M for freedom. on the main way. The relative lengths of these periods can be anything desired, within reasonable limits, as already described.

It is to be observed that I have described the timing device as spring actuated only. Where cost is a secondary consideration, this timing device will be constructed more substantially, especially where it is expected to carry a load such as that of a number of stations through the dotted line circuits in Fig. 4. Thus, instead of the spring motor and the ratchet actuated by the electromagnet 43, the timing device 8 and its shaft may in practice be driven by an electric motor having its circuit controlled by a pair of contacts opened and closed by a cam on the member 8, or the like. This cam may be coincident with the contact projection 9, as to its operation, to open the circuit of the motor whenever the contact 9 rests upon the contact l0, and to close it at all other times. In operation, the master relay I would initially close the circuit of the motor, which would start the disc or arm 8 around, whereupon the cam on the disc would pass away from the motor springs and allow the same to close, and to remain closed turning the timing device steadily until one complete rotation is effected, whereupon the cam will again open the motor springs, and as the circuit of the master relay has opened in the meantime, the timing mechanism will stop. Various other arrangements for this same purpose maybe devised or adapted from this or other arts without departure from my invention, and I Wish it understood that these are all included within the scope of the claims.

What I claim is:

1. A signaling system arranged at the intersection of a highway and a crossroad for regulating traflic, said system including a highway lamp circuit and a crossroad lamp circuit for the routine control of traffic, a pair of relays for alternately opening and closing said lamp circuits, circuits for said relays, an energizing winding and a locking winding on each relay, a circuit extending from each locking winding to a source of current, and adapted to be closed when the relay is energized, contacts on each relay adapted when that relay is energized to disable the locking circuit of the other, and a time controlled switch associated with said relays for alternately closing and opening the energizing windings on said relays, said switch being normally idle in an initial position with both said energizing circuits open so as to normally retain the highway circuit closed to permit highway traffic to cross the intersection, means actuated by a vehicle approaching energize said interlocking relays to successively signal the right of way to the crossroad and highway, said means including the time controlled switch and being operative for automatically restoring the switch, the relays, and the lamp circuits to their initial positions.

2. A street crossing signaling system including a pair of signal circuits, each circuit including a go signal on one street and a stop signal on the other street, a time controlled switching means for successively and alternately reversing the open and closed positions of the circuits for predetermined periods of time, a vehicle actuated means for initiating the operation of said time controlled switching means, said vehicle actuated means including energy storing means operated by the vehicle actuation for storing sufiicient energy to operate thetime switch through one complete cycle, and means operated by the time switch for disconnecting the vehicle actuated means during the operation of the time switch.

3. A street crossing signaling system including a pair of signal circuits, each signal circuit containing three signals, g0, caution and stop, one circuit normally showing a go signal on one street and the other circuit a stop signal on the other street, a time controlled switching means for showing a cycle of signals from go through caution to stop and then through caution to go and vice versa for the other circuit normally set at stop, a vehicle actuated means for initiating the operation of said time controlled switching means, said vehicle actuated means including energy storing means operated by the vehicle actuation for storing sufficient energy to operate the time switch through one complete cycle and means operated by the time switch for disconnecting the vehicle actuated means during the operation of the time switch.

4. A street crossing signaling system for interfering lanes thereat, including a pair of signaling circuits, one circuit including a stop signal for one lane and a go signal for an interfering lane, and the second circuit including a go signal for the said one lane, and a stop signal for said interfering lane, and control means for said signal circuits; at central traffic control including connections to said control means and also time control means, and when operative rendering said connections in one operative condition for a predetermined time to apply said control means to said signal circuits to energize one of said signal circuits, repeatedly alternated with a different operative condition to apply said control means to said signal circuits to energize the said other signal circuit for a predetermined time; a normally inactive time controlled mechanism, said mechanism, when inactive, applying said control means to said signal circuits to energize one signal circuit and deenergize the other signal circuit, and when activated, applying said control means to said signal circuits first to deenergize the said one signal circuit while energizing the said other signal circuit for a predetermined period, and thereafter returning to inactive condition, a device actuated by traffic in one of said lanes, means connected tosaid mechanism and operated when said device is actuated to activate said mechanism; and a switching mechanism operable when said central control is operating to disconnect the last said means from said mechanism whereby the central control connection is operative to operate said signal circuit control means.

ROY M. ALLEN. 

